<!DOCTYPE html>
<title>position:sticky elements should properly interact with margins</title>
<link rel="match" href="position-sticky-margins-ref.html" />
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="position:sticky elements should ignore margins when sticking, but consider them when making sure sticky elements do not escape their containing block" />

<style>
.group {
  display: inline-block;
  position: relative;
  width: 180px;
  height: 400px;
}

.scroller {
  position: relative;
  width: 150px;
  height: 300px;
  overflow-y: scroll;
  overflow-x: hidden;
}

.holder {
  width: 130px;
  height: 200px;
}

.sticky {
  position: sticky;
  background-color: green;
  top: 5px;
  margin: 15px;
}

.indicator {
  left: 15px;
  position: absolute;
  background-color: red;
}

.box {
  width: 100px;
  height: 100px;
}

.padding {
  height: 300px;
}
</style>
<script>
window.addEventListener('load', function() {
  document.getElementById('scroller1').scrollTop = 0;
  document.getElementById('scroller2').scrollTop = 60;
  document.getElementById('scroller3').scrollTop = 120;
});
</script>

<!-- Before sticking, the margin should be obeyed. -->
<div class="group">
  <div id="scroller1"  class="scroller">
    <div class="indicator box" style="top: 15px;"></div>
    <div class="holder">
      <div class="sticky box"></div>
    </div>
    <div class="padding"></div>
  </div>
</div>

<!-- Whilst stuck, the margin is irrelevant. -->
<div class="group">
  <div id="scroller2"  class="scroller">
    <div class="indicator box" style="top: 65px;"></div>
    <div class="holder">
      <div class="sticky box"></div>
    </div>
    <div class="padding"></div>
  </div>
</div>

<!-- The margin does count when making sure the sticky element does not escape
     its containing block. -->
<div class="group">
  <div id="scroller3"  class="scroller">
    <div class="indicator box" style="top: 100px;"></div>
    <div class="holder">
      <div class="sticky box"></div>
    </div>
    <div class="padding"></div>
  </div>
</div>

<div>You should see three green boxes above. No red should be visible.</div>
